Electrical insulator.



1 UNITED STATES PATENT OFFICE.

JoNA w. AYLSWORTH', OF EAST ORANGE, NEW JERSEY, ASSIGNOR, RY DIRECT AND MESNE SSIGNMENTS, mo THE HALOGEN PRODUCTS COMPANY, OF WEST ORANGE, NEW JERSEY, A CORPORATION or NEW JERSEY.

\ ELECTRICAL INSULA'IOR.

No Drawing.

Specification of Letters Patent.

Application filed March 17, 1911. Serial N o. 615,0404}.

Patented Apr. 28, 1914.

To all whom it may concern."

Be it known that I, JONAS W. AYLSwoRTH, a citizen of the United States, and a resident of East Orange, in the county of Essex and State of NewJersey, have invented certain new and'useful Improvements in Electrical Insulators, of which the following is a description.

My invention relates to liquid insulators into which electrical apparatus, such as transformer coils, are submerged, and the object of my invention is to provide a fluid insulation for the purpose possessing highly desirable qualities that are not possessed by.

the oils now in use for this, urpose.

A liquid insulator for e ectively insulating a transformer coil or other electrical apparatus immersed in the liquid should ossess certain properties for obtaining the est results in actual practice. The liquid should be highly dielectric, so as to resist the tendency of the current to leak or discharge from itsv conductor; it should possess great fluidity, so as to enter and fill in cracks or fissures that may be formed in the inaulating material and which unless filled are the cause of incipient leakage of current followed by eventual breaking down of the insulation; it should be non-hygroscopic, thereby resisting any tendency to absorb water, the presence of which is obviously detrif mental to the insulating properties of the liquid. It shouldhave a high specific gravity, so that if any Water enters the container in which the fluid is held it will float on the surface thereof, instead of entering the liquid or accumulating at the bottom to form an objectionable conducting layer; it should possess a low freezing point, so as to remain liqpid at low temperatures; it should possess a igh specific heating point and be able to rapidly dissipate heat, so as not to beaf fected by high temperatures and in case heat is developed by current leakage it will be rapidly dissipated; it should have a high boiling point, so that in case the liquid is heated it will not be volatilized or changed in character; at all times it should be chemically inert and stable. I have discovered a substance which possesses these desirable properties in a high degree and which may be cheaply produced. This liquid is the isomer of mono-chloro-naphthalene, which is produced by the chlorination of molten naphthalene under pressure at temperatures which may be ranged between 100 and 125 degrees centigrade until it has absorbed the required amount of chlorin, such a process, for example, being described and claimed in my patent dated March 2, 1909, and numbered-914,223. The determination as to the required amount of chlorin that may be ab-' sorbed by the naphthalene may be ascertained by weight orv by noting the amount of hydrochloric acid evolved or by testing a sample from time to time. After the chlorination is completed to the desired stage, the

product is distilled and the distillate boiled with a 10% solution of caustic soda or potash, and washed free of alkali.- After washing the with a 10% solution of caustic soda or pot-ash above the boiling point of water or by filtration through a Water-absorbing medium.

The oil may then be exposed to cold sufiicient to crystallize out any contained Solid modifications of the chloronaphthalene or higher substitution products thereof or free naphthalene, and the solid crystals may then be separated by filtration. The oil thus produced has a hi h specific gravity, much higher, in fact, t ian Water; is not easily in- I-COilS. With the oils now in use for insulatin purposes such protection is not aflorded. Wlien a higher viscosity is desired the oil may be thickened by dissolving therein by the aid of heat from 2% to 5% of rubber or other gum.

It is sometimes advantageous to dissolve in the oil an organic anh drid having the function of combining with traces of water if they should develop in the coils from 1mperfect drying of the same. Such anhydrids, which of the lators and whose hy also good insulators; the higher 5 as stearic acid and p Having now I claim as new by Letters Paten 1. A liquid ins apparatus may b a distilled chloro-na an alkali, substantial members 0 describe mselves are good insudrolyzed products are are the anhydrids of f the fatty acids, such almitic acid.

6. my invention, what therein and desire to secure t is as follows ulator into which electrical e submerged, consisting o.

phthalene treated with ly as described.

2. A liquid insulator into which electrical containing subs thalene, or high thereof, substantially as chlorinated na modifications of the tution pro moved, sub

4:. A liq ubmerged, consisting of hthalene treated with hich traces of free ald insulator into which electrical be submerged, comprisinga which solid higher substiducts described.

5. An insulating composition containing 09 liquid chlorinated naphthalene having an inflection in tetters Patent No. l 094,829.

lt is hereby certifie upon the application of Jona improvement in Electrical Insulators,

s W. Aylsworth, of

anhydrid dissolved therein, substantially as set forth.

6. An insulating composition containing liquid chlorinated naphthalene and an anhydrid substantially as set forth.

of a higher member of a fatty acid,

7. An insulating composition containing liquid chlorinated naphthalene having dissolved therein a small percentage of gum and an anhydrid, substantially as set forth.

8. An insulating composition containing liquid chlorinated naphthalene having solved therein a small percentage of rubber and an anhydrid, substantially as set forth.

9. An insulating composition. containing liquid chlorinated naphthalene having dissolved therein a small percentage of gum and an anhydrid of a higher :.nember of a fatty acid, substantially as set forth.

10. An insulating composition containing liquid chlorinated naphthalene having dis-- solved therein a small ercentage of rubber and an anhydrid of a higher member of a fatty acid, substantially as set forth.

This specification signed and witnessed this 10th da of March 1911.

dONAS W. AYLS WO'R'IH. Witnesses:

ANNA R. KLEHM, GnARnnon CHURCHILL.

d that in Letters Patent No. 1,094,829, granted April 28, 1914,

East Orange, New Jersey, for an an error appears in the printed specification requiring correction as follows: Page 1, strike out line 71 and insert the words oil may befreetlfrom water by heating;

read with this corre [scan] ction therein that the same may conform and that the said Letters Patent should be to the record of the a. F. wnrrnnnan,

Acting Commissimwr offaimts. v, 

